PROGEESSION ON AND IN THE WATER. 



85 



rather than on either side of it. The extremities are con- 

 sequently employed in the best manner possible for developing 

 their power and reducing the friction to forward motion 

 caused by their action. This arrangement greatly increases 

 the length of the effective stroke, both of the arms and legs, 

 this being equal to nearly half an ellipse. Thus when the 

 left arm and leg are thrust forward, the arm describes the 

 curve a h (fig. 42), the leg e describing a similar curve. As 

 the right side of the body virtually recedes when the left 

 side advances, the right arm describes the curve c while 

 the left arm is describing the curve a h; the right leg / 

 describing a curve the opposite of that described by e (com- 

 pare arrows). The advancing of the right and left sides of 



Fig. 42. — Overliand S^wimming. —Origi7ial. 



the body alternately, in a nearly straight line, greatly couv 

 tributes to continuity of motion, the impulse being applied 

 now to the right side and now to the left, and the limbs 

 being disposed and worked in such a manner as in a great 

 measure to reduce friction and prevent dead points or halts. 

 When the left arm and leg are being thrust forward (a b, e 

 of fig. 42), the right arm and leg strike very nearly directly 

 backward {c d, f of fig. 42). The right arm and leg, and the 

 resistance which they experience from the water consequently 

 form a point d\ippui for the left arm and leg ; the two sides 

 of the body twisting and screwing upon a moveable fulcrum 

 (the water)— an arrangement which secures a maximum of 

 propulsion with a minimum of resistance and a minimum of 

 slip. The propulsive power is increased by the concave surfaces 

 of the hands and feet being directed backwards during the back 

 stroke, and by the arms being made to throw their back 

 water in a slightly outward direction, so as not to impede 

 the advance of the legs. The overhand method of swimming 



